Guilds were built on the apprenticeship system, in which boys around seven years of age were sent to live with masters for fixed terms of five to ten years. An apprentice worked directly under the tutelage and supervision of the master, who frequently assumed rights as the child's legal guardian. Apprentices learned the craft from the bottom up, not through lecture or theory but through action: mixing paint, preparing canvases, sharpening chisels. They cooperated and competed within a hierarchy,
